My Forrester colleagues Ted Schadler and John McCarthy have written about the differences between Systems of Reference (SoR) and Systems of Engagement (SoE) in the customer-facing systems and mobility, but after further conversations with some very smart people at IBM, I think there are also important reasons for infrastructure architects to understand this dichotomy. Scalable and flexible systems of engagement, engagement, built with the latest in dynamic web technology and the back-end systems of record, highly stateful usually transactional systems designed to keep track of the “true” state of corporate assets are very different animals from an infrastructure standpoint in two fundamental areas:

Suitability to cloud (private or public) deployment – SoE environments, by their nature, are generally constructed using horizontally scalable technologies, generally based on some level of standards including web standards, Linux or Windows OS, and some scalalable middleware that hides the messy details of horizontally scaling a complex application. In addition, the workloads are generally highly parallel, with each individual interaction being of low value. This characteristic leads to very different demands on the necessity for consistency and resiliency.